The present invention relates to a liquid crystal display of an active matrix type employing thin-film transistors (TFTs), and a method of fabricating such a liquid crystal display.
The active matrix liquid crystal display has, for example, non-linear devices (switching devices) and pixel electrodes arranged in a matrix. Because the liquid crystal at each pixel is theoretically driven continuously (duty ratio of 1.0), the active matrix type has better contrast than a so-called simple matrix type using a time-division driving method, and is therefore becoming an essential technology particularly for color liquid crystal displays. Among representative switching devices is a thin-film transistor (TFT).
The liquid crystal display device, for example, comprises: a liquid crystal display panel (liquid crystal display element); a backlight arranged beneath the liquid crystal display panel to supply light to the liquid crystal display panel; a printed circuit board arranged outside the liquid crystal display panel and formed with a liquid crystal drive circuit; a molded frame for holding these members; and a metal frame accommodating these members and formed with a liquid crystal display window. The liquid crystal display panel has two transparent glass substrates stacked together with a predetermined space therebetween in such a way that those surfaces of the two transparent glass substrates which are laminated with display pixel electrodes formed of a transparent conductive film and with an orientation film face each other. These two substrates are bonded together by a sealing material provided between, and along the edge of, the substrates like a frame. At the same time, a liquid crystal is loaded inside the frame-like sealing material between the substrates from a liquid crystal supply port formed in the sealing material and then the supply port is sealed.
The surface of a first of the two transparent glass substrates forming the liquid crystal display panel carries transparent pixel electrodes, each of which, together with a switching element or thin-film transistor, is formed in an intersection region enclosed by two adjacent scan signal lines (called gate signal lines or horizontal signal lines, extending laterally and arranged in a vertical direction, and serving as gate electrodes of thin-film transistors serving as the switching elements) and two adjacent video signal lines (called drain signal lines, data signal lines or vertical signal lines, extending vertically and arranged in a lateral direction and serving as drain electrodes of the thin-film transistors).